eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1053
1063
460
Annihilator-small submodules
T. Amouzegar Kalati
t.amoozegar@umz.ac.ir
1
D. Keskin Tutuncu
keskin@hacettepe.edu.tr
2
Mazandaran University, Department of mathematic
Hacettepe University, Mathematics Department
Let $M_R$ be a module with $S=End(M_R)$. We call a submodule $K$ of $M_R$ annihilator-small if $K+T=M$, $T$ a submodule of $M_R$, implies that $ell_S(T)=0$, where $ell_S$ indicates the left annihilator of $T$ over $S$. The sum $A_R(M)$ of all such submodules of $M_R$ contains the Jacobson radical $Rad(M)$ and the left singular submodule $Z_S(M)$. If $M_R$ is cyclic, then $A_R(M)$ is the unique largest annihilator-small submodule of $M_R$. We study $A_R(M)$ and $K_S(M)$ in this paper. Conditions when $A_R(M)$ is annihilator-small and $K_S(M)=J(S)=Tot(M, M)$ are given.
http://bims.iranjournals.ir/article_460_cc483dbffd072a63c2e7822e0bcb3c67.pdf
small submodules
annihilators
annihilator-small submodules
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1065
1078
461
Determinants and permanents of Hessenberg matrices and generalized Lucas polynomials
K. Kaygisiz
kenankaygisiz@yahoo.com
1
A. Sahin
adem.sahin@gop.edu.tr
2
Gaziosmanpasa University Faculty of Science and Art Department of Mathematics
Gaziosmanpasa University
In this paper, we give some determinantal and permanental representations of generalized Lucas polynomials, which are a general form of generalized bivariate Lucas p-polynomials, ordinary Lucas and Perrin sequences etc., by using various Hessenberg matrices. In addition, we show that determinant and permanent of these Hessenberg matrices can be obtained by using combinations. Then we show, the conditions under which the determinants of the Hessenberg matrix become its permanents.
http://bims.iranjournals.ir/article_461_614511c7f595e147b7d12b7d884a46e1.pdf
Generalized Lucas polynomials
generalized Perrin polynomials
Hessenberg matrix
determinant
permanent
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1079
1097
462
Gorenstein projective objects in Abelian categories
H. Cheng
xiangyun23@sina.com.cn
1
X. Zhu
zhuxs@nju.edu.cn
2
Department of Mathematics, Nanjing University, Nanjing 210093, China
Department of Mathematics, Nanjing University, Nanjing 210093, China
Let $mathcal {A}$ be an abelian category with enough projective objects and $mathcal {X}$ be a full subcategory of $mathcal {A}$. We define Gorenstein projective objects with respect to $mathcal {X}$ and $mathcal{Y}_{mathcal{X}}$, respectively, where $mathcal{Y}_{mathcal{X}}$=${ Yin Ch(mathcal {A})| Y$ is acyclic and $Z_{n}Yinmathcal{X}}$. We point out that under certain hypotheses, these two Gorensein projective objects are related in a nice way. In particular, if $mathcal {P}(mathcal {A})subseteqmathcal {X}$, we show that $Xin Ch(mathcal {A})$ is Gorenstein projective with respect to $mathcal{Y}_{mathcal{X}}$ if and only if $X^{i}$ is Gorenstein projective with respect to $mathcal {X}$ for each $i$, when $mathcal {X}$ is a self-orthogonal class or $X$ is $Hom(-,mathcal {X})$-exact. Subsequently, we consider the relationships of Gorenstein projective dimensions between them. As an application, if $mathcal {A}$ is of finite left Gorenstein projective global dimension with respect to $mathcal{X}$ and contains an injective cogenerator, then we find a new model structure on $Ch(mathcal {A})$ by Hovey's results in cite{Ho} .
http://bims.iranjournals.ir/article_462_bdb19acaedd836465e241a86c9c3a04e.pdf
$mathcal {X}$-Gorenstein projective object
$mathcal {X}$-Gorenstein projective dimension
$mathcal {F}$-preenvelope
cotorsion pair
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1099
1115
463
Some classes of strongly clean rings
H. Chen
huanyinchen@aliyun.com
1
Department of Mathematics, Hangzhou Normal University, 310036, Hangzhou, China
A ring $R$ is a strongly clean ring if every element in $R$ is the sum of an idempotent and a unit that commutate. We construct some classes of strongly clean rings which have stable range one. It is shown that such cleanness of $2 imes 2$ matrices over commutative local rings is completely determined in terms of solvability of quadratic equations.
http://bims.iranjournals.ir/article_463_8ef77b04cf0305fbaba0af11fc78b480.pdf
strongly $J_n$-clean ring, $2 imes 2$ matrix
Local ring
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1117
1123
464
Characteristic function of a meromorphic function and its derivatives
J. Wu
44976882@qq.com
1
Z. Wu
wuzj52@hotmail.com
2
Xianning Vocational and Technical College, P.O. Box 437100, Xianning, P. R. China
School of Mathematics and Statistics, Hubei University of Science and Technology, P.O. Box 437100, Xianning, P. R. China
In this paper, some results of Singh, Gopalakrishna and Kulkarni (1970s) have been extended to higher order derivatives. It has been shown that, if $sumlimits_{a}Theta(a, f)=2$ holds for a meromorphic function $f(z)$ of finite order, then for any positive integer $k,$ $T(r, f)sim T(r, f^{(k)}), rrightarrowinfty$ if $Theta(infty, f)=1$ and $T(r, f)sim (k+1)T(r, f^{(k)}), rrightarrowinfty$ if $Theta(infty, f)=0.$
http://bims.iranjournals.ir/article_464_28b526931ff60ee50847aaedcce35cc0.pdf
characteristic function
Nevanlinna's deficiency
maximum deficiency sum
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1125
1135
465
Common fixed points of a finite family of multivalued quasi-nonexpansive mappings in uniformly convex Banach spaces
A. Bunyawat
aunyarat@mwit.ac.th
1
S. Suantai
suthep.s@cmu.ac.th
2
Department of Mathematics, Faculty of Science, Chiang Mai University 50200, Chiang Mai, Thailand
Department of Mathematics, Faculty of Science, Chiang Mai University 50200, Chiang Mai, Thailand
In this paper, we introduce a one-step iterative scheme for finding a common fixed point of a finite family of multivalued quasi-nonexpansive mappings in a real uniformly convex Banach space. We establish weak and strong convergence theorems of the propose iterative scheme under some appropriate conditions.
http://bims.iranjournals.ir/article_465_9924dedbbb514316780466391a2a981d.pdf
Finite family of multivalued quasi-nonexpansive mappings
common fixed point
one-step iterative
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1137
1158
466
Module approximate amenability of Banach algebras
H. Pourmahmood-Aghababa
h_p_aghababa@tabrizu.ac.ir
1
A. Bodaghi
abasalt.bodaghi@gmail.com
2
Tabriz University, Tabriz, Iran
Islamic Azad University of Garmsar, Garmsar, Iran
In the present paper, the concepts of module (uniform) approximate amenability and contractibility of Banach algebras that are modules over another Banach algebra, are introduced. The general theory is developed and some hereditary properties are given. In analogy with the Banach algebraic approximate amenability, it is shown that module approximate amenability and contractibility are the same properties. It is also shown that module uniform approximate (contractibility) amenability and module (contractibility, respectively) amenability for commutative Banach modules are equivalent. Applying these results to l^1 (S) as an l^1 (E)-module, for an inverse semigroup S with the set ofidempotents E, it is shown that l^1(S) is module approximately amenable (contractible) if and only if it is module uniformly approximately amenable if and only if S is amenable.Moreover, l^1(S)^{**} is module (uniformly) approximately amenable if and only if an appropriate group homomorphic image of S is finite.
http://bims.iranjournals.ir/article_466_605a2ac8ad2936a6371f9bda251cbb65.pdf
Module derivation
Module amenability
Approximately inner
Inverse semigroups
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1159
1180
467
The streamline diffusion method with implicit integration for the multi-dimensional Fermi Pencil Beam equation
E. Kazemi
e.kazemi@math.iut.ac.ir
1
Isfahan University of Technology, Isfahan, Iran
We derive error estimates in the appropriate norms, for the streamlinediffusion (SD) finite element methods for steady state, energy dependent,Fermi equation in three space dimensions. These estimates yield optimal convergencerates due to the maximal available regularity of the exact solution.High order SD method together with implicit integration are used. The formulationis strongly consistent in the sense that the time derivative is includedin the stabilization term. Here our focus is on theoretical aspects of the h andhp approximations in SD settings.
http://bims.iranjournals.ir/article_467_6a62e34662811d8fa55d39ce9ae949e3.pdf
Fermi equation
particle beam
streamline diffusion
Backward Euler
Stability
convergence
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1181
1188
468
Some properties of marginal automorphisms of groups
M. R. Moghaddam
rezam@ferdowsi.um.ac.ir
1
H. Safa
hesam.safa@gmail.com
2
Khayyam Higher Education Institute, Mashhad , Iran
Department of Pure Mathematics, Faculty of Mathematical Sciences, Ferdowsi University of Mashhad, P.O. Box 1159, Mashhad, Iran
AbstractLet W be a non-empty subset of a free group. The automorphism of a group G is said to be a marginal automorphism, if for all x in G,x^−1alpha(x) in W^*(G), where W^*(G) is the marginal subgroup of G.In this paper, we give necessary and sufficient condition for a purelynon-abelian p-group G, such that the set of all marginal automorphismsof G forms an elementary abelian p-group.
http://bims.iranjournals.ir/article_468_508d725781c352662ec2e65218cfc8da.pdf
Primary
20D45, 20F28. Secondary
20E05, 20E36
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1189
1212
470
On the non-split extension group $2^{6}{^{cdot}}Sp(6,2)$
A. Basheer
ayoubbasheer@gmail.com
1
J. Moori
jamshid.moori@nwu.ac.za
2
Universities of KwaZulu-Natal & Khartoum
North-West University
In this paper we first construct the non-split extension $overline{G}= 2^{6} {^{cdot}}Sp(6,2)$ as a permutation group acting on 128 points. We then determine the conjugacy classes using the coset analysis technique, inertia factor groups and Fischer matrices, which are required for the computations of the character table of $overline{G}$ by means of Clifford-Fischer Theory. There are two inertia factor groups namely $H_{1} = Sp(6,2)$ and $H_{2} = 2^{5}{:}S_{6},$ the Schur multiplier and hence the character table of the corresponding covering group of $H_{2}$ were calculated. Using information onconjugacy classes, Fischer matrices and ordinary and projective tables of $H_{2},$ we concluded that we only need to use the ordinary character table of $H_{2}$ to construct the character table of $overline{G}.$ The Fischer matrices of $overline{G}$ are all listed in this paper. The character table of $overline{G}$ is a $67 times 67$ integral matrix, it has been supplied in the PhD Thesis of the first author, which could be accessed online.
http://bims.iranjournals.ir/article_470_17caff41609267a65438eee7c4988ea4.pdf
Group extensions
symplectic group
character table
Clifford theory
inertia groups
Fischer matrices
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1213
1222
471
The nc-supplemented subgroups of finite groups
S. Guo
710442986@qq.com
1
S. Liu
s.t.liu@yandex.com
2
W. Shi
wjshi@suda.edu.cn
3
School of Science, Sichuan University of Science & Engineering, 643000, Zigong, P. R. China
School of Science, Sichuan University of Science & Engineering, 643000, Zigong, P. R. China
School of Mathematics and Statistics, Chongqing University of Arts and Sciences, 402160, Chongqing, P. R. China
A subgroup $H$ is said to be $nc$-supplemented in a group $G$ if there exists a subgroup $Kleq G$ such that $HKlhd G$ and $Hcap K$ is contained in $H_{G}$, the core of $H$ in $G$. We characterize the supersolubility of finite groups $G$ with that every maximal subgroup of the Sylow subgroups is $nc$-supplemented in $G$.
http://bims.iranjournals.ir/article_471_8d89af79f6fda3147747ae4a8991ca77.pdf
soluble group
$nc$-supplemented subgroup
Normal subgroup
Supersoluble group
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1223
1248
472
Bifurcation of limit cycles from a quadratic reversible center with the unbounded elliptic separatrix
L. Peng
penglp@buaa.edu.cn
1
Y. Lei
yazhi177@126.com
2
School of Mathematics and System Sciences, Beihang University
School of Mathematics and System Sciences, Beihang University/The 24th Middle School of Beijing
The paper is concerned with the bifurcation of limit cycles in general quadratic perturbations of a quadratic reversible and non-Hamiltonian system, whose period annulus is bounded by an elliptic separatrix related to a singularity at infinity in the poincar'{e} disk. Attention goes to the number of limit cycles produced by the period annulus under perturbations. By using the appropriate Picard-Fuchs equations and studying the geometric properties of two planar curves, we prove that the maximal number of limit cycles bifurcating from the period annulus under small quadratic perturbations is two.
http://bims.iranjournals.ir/article_472_a02b2450a1b3745f35b4010b9b0ab4d3.pdf
a quadratic reversible and non-Hamiltonian center
bifurcation of limit cycles
a period annulus
the Abelian integral
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1249
1260
473
An iterative method for the Hermitian-generalized Hamiltonian solutions to the inverse problem AX=B with a submatrix constraint
J. Cai
caijing@hutc.zj.cn
1
Huzhou Teachers College
In this paper, an iterative method is proposed for solving the matrix inverse problem $AX=B$ for Hermitian-generalized Hamiltonian matrices with a submatrix constraint. By this iterative method, for any initial matrix $A_0$, a solution $A^*$ can be obtained in finite iteration steps in the absence of roundoff errors, and the solution with least norm can be obtained by choosing a special kind of initial matrix. Furthermore, in the solution set of the above problem, the unique optimal approximation solution to a given matrix can also be obtained. A numerical example is presented to show the efficiency of the proposed algorithm.
http://bims.iranjournals.ir/article_473_ef7d4a2fd05bb1efdab593d07d72c417.pdf
Inverse problem
Hermitian-generalized Hamiltonian matrix
Submatrix constraint
Optimal approximation
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1261
1272
474
Fixed points for E-asymptotic contractions and Boyd-Wong type E-contractions in uniform spaces
A. Aghanians
a.aghanians@dena.kntu.ac.ir
1
K. Fallahi
k_fallahi@dena.kntu.ac.ir
2
K. Nourouzi
nourouzi@kntu.ac.ir
3
K.N. Toosi University of Technology
K.N. Toosi University of Technology
K.N. Toosi University of Technology
In this paper we discuss on the fixed points of asymptotic contractions and Boyd-Wong type contractions in uniform spaces equipped with an E-distance. A new version ofKirk's fixed point theorem is given for asymptotic contractions and Boyd-Wong type contractions is investigated in uniform spaces.
http://bims.iranjournals.ir/article_474_a4fea9f574e47dc292fc6e7f8ec1a8a0.pdf
Separated uniform space
E-asymptotic contraction
Boyd-Wong type
E-contraction
fixed point
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2013-12-15
39
6
1273
1281
346
2-recognizability of the simple groups $B_n(3)$ and $C_n(3)$ by prime graph
M. Foroudi Ghasemabadi
mahnaz_mat@yahoo.com
1
A. Iranmanesh
iranmana@yahoo.com
2
N. Ahanjideh
ahanjideh.neda@sci.sku.ac.ir
3
Tarbiat Modares University
Tarbiat Modares University
University of Shahre-kord
Let $G$ be a finite group and let $GK(G)$ be the prime graph of $G$. We assume that $ngeqslant 5 $ is an odd number. In this paper, we show that the simple groups $B_n(3)$ and $C_n(3)$ are 2-recognizable by their prime graphs. As consequences of the result, the characterizability of the groups $B_n(3)$ and $C_n(3)$ by their spectra and by the set of orders of maximal abelian subgroups are obtained. Also, we can conclude that the AAM's conjecture is true for the groups under study.
http://bims.iranjournals.ir/article_346_1295fb2d30416b6530013ae8d990f863.pdf
Prime graph
classification of finite simple groups
recognition
spectrum